Pt/Ag‐PEG‐Ce6 Nanosystem with Enhanced Near‐Infrared Absorption and Peroxidase‐Like Activity for Synergistic Photodynamic/Photothermal Therapy

Noble metals and their alloy-based nanomaterials are widely used in biomedicine, especially in the fields of photodynamic therapy (PDT) and photothermal therapy (PTT) on tumors, due to their remarkable physicochemical properties. Nonetheless, novel doping strategies with unexpected efficacies are still challenging and formidable. Herein, a photosensitizer-alloy nanosystem is designed for highly efficient PDT and PTT. Specifically, the optimized Pt/Ag alloy nanoparticles are facilely synthesized in one step at room temperature and are simultaneously endowed with enhanced peroxidase-like activity and photothermal conversion, and further activated cytotoxic singlet oxygen (O-1(2)) productivity after covalent functionalization of chlorin e6 (Ce6). A small amount of Ag doping can kill two birds with one stone by simultaneously enhancing the synergistic PDT and PTT potential of Pt/Ag-PEG-Ce6 nanoparticles. Both in vitro and in vivo experimental results indicate that the significant temperature increase triggered by 808 nm laser and a large amount of toxic O-1(2) excited by 671 nm laser synergistically and strongly kill tumor cells. Therefore, through proper doping and improved physicochemical properties, this nanosystem achieves effective PDT and PTT of tumors and also inspires the advanced design of noble metal-based nanomedicine.